Genth.] °^ [Sep. 19 > 



b. Another superb specimen was presented to me by Col. Jos. Willcox, 

 who collected it a short time ago at Swannanoa Gap, Buncombe County, 

 North Carolina. It consists of a fragment of an irregular hexagonal 

 prism of corundum of about two inches in length and one inch in thick- 

 ness, of a deep blue and white color, and showing the perfect rhombohe- 

 dral cleavage ; it is surrounded by pale blueish-white cyanite and 

 damourite. The surface of the corundum appears much eaten and the 

 specimen is a beautiful illustration of the alteration of corundum into the 

 two other minerals. 



c. A third specimen I received about two years ago from Mr. Hanna, 

 Assistant Assayer of the Mint in Charlotte, North Carolina. It comes 

 from Wilkes County, North Carolina. At that time I had no idea of the 

 importance, in a scientific point of view, of some insignificant particles 

 of corundum in cyanite, and procured the specimens only on account of 

 the beauty of the latter. Mr. Hanna had another piece, which, if my 

 memory serves me right, contains a mass of corundum of about one inch 

 in diameter. The cyanite has an impure blueish-greenish color and 

 coarsely bladed columlar crystals and crystalline masses, some of the 

 blades 1 to li inches across. Several small fragments and grains of 

 corundum, of a gray to a reddish-brown color are visible in the mass of 

 cyanite, one of them showing the usual striation very distinctly. A 

 minute quantity of damourite is also present. 



I shall now enter into the discussion of some points with reference to the 

 occurrence of corundum in Gaston and Rutherford Counties, North Caro- 

 lina, which form a close connection with the remarks just made, although 

 I may be compelled to anticipate some facts, which should not yet be 

 discussed. 



At Crowder's Mountain, and Clubb's Mountain, in Gaston County, 

 and at a recently discovered locality in Eutherford County, North Caro- 

 lina, corundum is found massive and in crystalline pieces, sometimes 

 showing a hexagonal form ; its color is from deep blue to purple, and 

 grayish-blue intermixed with white. The unaltered corundum is some- 

 what ferruginous and invariably contaius crystals of rutile of different 

 sizes disseminated through the whole mass. This corundum, however, 

 is sometimes altered into a compact margarite, which coats the blue crys- 

 tals, but generally into damoui'ite and cyanite, which are associated with 

 gold, granular quartz, etc. This alteration, however, goes frequently 

 farther and leaves not a trace of corundum, and often nothing but sco- 

 riaeceous masses, the cavities frequently still containing small crystals of 

 cyanite coated with a brownish-black limonite, and rutile in brilliant 

 crystals or coated in the same manner. But there are two new products 

 of the alteration associated with these, pyrophyllite and lazulite. The 

 same association of cyanite, rutile, pyrophyllite and lazulite in an arena- 

 ceous sandrock is found at Graves Mountain, Lincoln County, Georgia, 

 and although as far as I am aware, corundum has never been found at 

 this place, there can be very little doubt that at this locality also all these 



